Apparatus for spraying traveling materials



April'25; 1950 w. R.. GAYTHWAITE:

APPARATUS FOR SPRAYING TRAVELING MATERIALS 3 Sheds-Sheet 1.

Filed April 25, 1947 nuooo o gzwa z m m April 25, 1950 w. R. GAYTHWAITE 2,505,179

' APPmTus FOR SPRAYING TRAVELING MATERIALS Filed April 25, 194'? s Sheets-Sheet 2 A ril (25, 11950 W. R. GAYTHWLAITE APPARATUS FOR SPRAYING TRAVELING MATERIALS Filed April 23, 1947 3 Sheets-Sheet 3 Patented Apr. 25, 1950 APPARATUS FOR SPRAYING TRAVELING MATERIALS Wilson R. Gaythwaite, Glasgow, Scotland, assignor to W 8; J Martin Limited, Glasgow, Scotland, a British company Application April 23, 1947, Serial No. 743,273 In Great Britain May 2, 1948 3 Claims. 1

This invention relates to an improved apparatus for spraying travelling materials.

In a number of industrial processes materials are treated with liquids by passing them in the form of a continuous web, or by transporting them on a conveyor belt, through a liquid spray.

Fabric lengths, textile piece goods, paper, and miscellaneous articles, may be subjected to processes of the kind for the purpose of dyeing, impregnating, forming films or coatings, and so on. A particularly valuable application of this process is to be found in the treatment of hides and skins in the leather industry, and. in particular in the continuous and automatic application of a spray film of finish materialto leather.

It is generally desirable in such processes to ensure that all parts of the travelling material receive a uniform application of spray, and it is an object of the invention to provide a machine in which this is achieved.

According to the invention there is provided an apparatus for spraying travelling materials, wherein a liquid sprayer is adapted to be reciprocated across the path of travel of the said materials, and wherein means are provided for controlling the rate of flow from the sprayer in accordance with the instantaneous speed thereof, so as to give a substantially uniform delivery of spray over the whole width of the said materials.

Preferably the rate of flow is controlled by a control valve actuating member mounted on the sprayer and co-operating with a fixed cam or template surface.

The sprayer may for example be reciprocated with a substantially simple harmonic motion, and in this case the contour of the cam or template should be substantially a sine curve. A motion of this kind may be imparted to the sprayer by means of a four-bar linkage.

In order that the invention may be well understood, one embodiment thereof will now be described and illustrated with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic side view of a machine for the application of a spray film of finish material to leather, with certain of the parts removed,

Fig. 2 is a plan view thereof,

Fig. 3 is a cross-section on the line III-III of Fig. 2.

Fig. 4 isan enlarged detail cross-sectional view on the line IVIV of Fig. 3,

Fig. 5 is an enlarged cross-sectional view taken on the line III-III of Fig. 2, but in the reverse direction, showing a modified form of cam,

Fig. 6 is a diagrammatic elevation of the opposite side from Fig. 1 showing control means for-the modified cam system of Fig. 5, and

Fig. 7 is an enlarged detail partial view of a cross-section on the line VII-VII of Fig. 5.

Referring now to the drawings, a continuous moving wire-mesh conveyor belt I runs over an idler roller 2 and is driven by a roller 3 which in turn is driven from a motor 4 via a system of belting and reduction pulleys mounted on counter shafts 5, 6. The belt I is arranged to move through a spray cabinet I and a heating cabinet 8, heated by a steam coil 9. A trough l extends below the upper run of the belt and communicates through apertures II with an exhaust duct I2. Two pairs of parallel guides l3 extend horizontally across the upper part of the spray cabinet. Brackets I4 are slidably mounted on the guides l3 and carry pivotally mounted spray guns l5. Screws l6, having knurled heads for ease of operation, are provided for angular adjustment of the spray guns in their pivotal mounting. Each gun l has a control valve trigger in the form of a cranked lever arm ll having a forked end carrying a roller l8 which co-operates with a fixed cam l9 extending across the cabinet parallel to the guides l3. A crank pin on a disc pulley 2|, which is mounted on the countershaft 6, is linked bymeans of a connecting rod 22 to a lever 23 pivotally mounted at 24 on the base of the machine so as to form a fourbar linkage. A cross-piece 25 is provided on the lever 23 and is arranged to move over arcuate guides 26 so as to guide the lever 23 in its oscillation. An endless leather belt 21 is connected to the cross-piece 25 and to thespray gun brackets l4 and runs around four guide rollers 28. A distributor head 29 is mounted for rotation about a vertical axis in a ball bearing 30 in the uppermost part of the spray cabinet. Flexible pipes 3|, 32 supply compressed air and finishing liquid respectively to the distributor head: Flexible pipes 33, 33a convey compressed air and finishing liquid respectively from the distributor head 29 to the guns l5.

In operation, the conveyor belt feeds skins slowly first through the spray cabinet and then through the drying cabinet. The skins are sprayed in the spray cabinet and excess spray fumes are continuously exhausted through the trough and exhaust duct below the conveyorbelt.

The skins then pass below the steam coil in the heating cabinet and are dried. The rotary motion of the crank pin 2| is transformed by the four-bar linkage into a substantially simple harits stroke, and are momentarily closed at the end.

of each"'stroke when the sprayer is momentarily stationary. i In order to adjust the device so that the valve along a surface of the said respective cam rail which latter is contoured substantially as a sine curve so as to vary the rate of flow from said liquid-sprayers in accordance with the instantaneous speed thereof so as to give a substantially uniform delivery of spray over the whole widthof said material's: I

only just closes at the end of the stroke, each gun l may'be adjusted by means of the screw l6 to rock it about its pivotal mounting. I

In the modification shown in Figures 5 to 7, an adjustable cam 19a is provided instead of the fixed cam. This cam is in the form of an eccentricalLv turned rod which may be rotated to vary the lift which 'it exerts on the cam follower roller l8. The cam is shown in Figures 5 and 7 in the maximum lift position, in which it pre- 2. Apparatus for spraying travelling materials comprising a liquid-sprayer mounted for reciprocating movement, means for conveying said materials beneath said liquid-sprayer, means for reciprocating said liquid-sprayer across the path of travel of said materials, a control valve incorporated in said liquid-sprayer, a valve-actuating member having a cam follower and operable to vary the opening of said control valve, a cam rail having a plurality of different cam-profiles iand angularly adjustable about its axis to presents a sine curve of maximum amplitude to the cam follower. As the cam is rotated the contour presented is a sine curve of decreasing amplitude, until after rotation through 180 the amplitude has become zero and a long fiat is presented to the cam follower.

The position of the cam may be adjusted by means of the hand wheel 34. Arms 35 are mounted on the shafts of the cam 19a and are secured by means of set screws 36. The two arms 35 are linked by a connecting rod 31, which extends to the delivery end of the machine, where it is connected to a rack and pinion device 38 operated by a hand wheel 39. Rotation of the hand wheel 39 causes the connecting rod 31 to move and the arms 35 to turn, altering the setting of the cams I90. Control may conveniently be exercised by an operator who also takes the finished skins off the machine.

Fig. ,6 also shows an arrangement for washing the conveyor belt to remove any finishing liquid before a fresh pass through the spray cabinet. This arrangement consists of an extension pipe 40 carrying the condensate from the steam heating coil via a steam trap 4| to an orifice 42 where the hot condensate water is delivered on to the lower run of the conveyor belt. The water is then collected in the tray 43 and evacuated through the waste pipe 44. g

I claim:

1. Apparatus for spraying travelling materials comprising an endless conveyor belt for transporting said materials, two liquid-sprayers slidably mounted for reciprocation in opposite directions in mutually parallel paths above and across the path of travel of said materials, a rotary driving shaft for said belt, a four-bar linkage operatively connected to said driving shaft, an endless band running over a plurality of guiderollers and connected toisaid linkage and to said liquid-sprayers, drive-means for transmitting a sent to said valve-actuating member follower a series of different cam profiles having different lifts, the follower ofv said valve-actuating member being in contact with and adapted to travel along and co-operate with the cam profile presented thereto to vary the opening of the said controlvalve in accordance with the instantaneous speed of said liquid-sprayer, each of said different cam profiles being adapted when presented to said valve-actuating member to give a different maximum opening of said control valve.

3. Apparatus for spraying travelling materials comprising an endless conveyor belt for transporting said materials, two liquid-sprayers slidably mounted for reciprocation in opposite directions in mutually parallel paths above and across the path of travel of said materials, a rotary driving shaft for said belt, a four-bar linkage operatively connected to said driving shaft, an endless band running over a plurality of vertical guide-rollers connected to said linkage and to said liquid-sprayers so as to transmit a subtantially simple harmonic reciprocating motion to said liquid-sprayers, a separate control valve incorporated in each said liquid-sprayer, a separate valve-actuating member operable to vary the opening of each said control valve, a follower connected with each said valve-actuating member, a cam rail having a plurality of diflerent cam-profiles and angularly adjustable about its axis to present to the follower of said valveactuating member a series of different cam profiles having diiferent lifts, each said valve-actuating member follower being in contact with said cam rail and adapted to travel along and co-operate with the cam profile presented thereto to vary the opening of its said respective control-valve in accordance with the instantaneous speed of its said respective liquid-sprayer, each of said different cam profiles being adapted when presented to said respective valve-actuating member to give a different maximum opening to said respective control valve.

- WILSON R. GAYTHWAITE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

